Automatic shifting power transmissions generally include a plurality of torque-transmitting mechanisms, such as clutches and brakes. These mechanisms are fluid applied mechanisms, which have a fluid source directed to the apply piston of the respective torque-transmitting mechanism. The fluid source is designed to have a plurality of control valves, which open and close to control the application of pressure to and from the torque-transmitting mechanism. When the torque-transmitting mechanism is to be applied, the valve is opened and fluid pressure is directed from a source of substantially constant apply pressure to return the torque-transmitting mechanism applied. When it is desired to release the torque-transmitting mechanism, the oil source at the torque-transmitting mechanism is decreased. These systems require that the source pressure be continuously made available to the valve mechanism in order to retain the torque-transmitting mechanism in the applied state.